package ch05;public class Pillar2 {
	Geometry bottom;
	double height;
	Pillar2 (Geometry bottom,double height) {
		this.bottom = bottom; this.height = height;
	}
	public double getVolume() {
		if(bottom==null) {
			System.out.println("没有底，无法计算体积");
			return -1;
		}
		return bottom.getArea()*height;
	}
}
